The kinetics of catalase reaction by soil profile of unreclaimned and reclaimed with different amounts of saline soils of Ararat-plain (Armenia) has been studied at the temprature interval 288-303 K and in large initial substrate concentration range. It has been established that those soils possess very low catalase activity. With the decrease of salt concentration in the upper layers of well- and semi-reclaimed saline soils, the values Wmax, in Michaelis-Menten equation increase, and the activation energy of enzyme-substrate complex decay decreases. It has been assumed that the low enzymatic activity is due to unfavourable changes in colloid-chemical properties of the said soils.